Use of spin-labelling techniques to probe the dynamics of He+ ion neutralization at clean metal surfaces

Recent experiments have revealed a marked correlation in the spins of the e lectrons involved in Auger neutralization of(polarized) He+ ions incident o n a dean Au(100) surface. A theoretical model is discussed which suggests t hat the experimental data can be explained by considering the perturbation in surface electronic structure induced by the presence of the ion. The fac tors that influence the induced density of states and its spin dependence a re considered including the surface work function, the widths of the atomic levels, and the ion velocity parallel to the surface. The results indicate that comparisons between theory and experiment can provide new insights in to the dynamics of ion neutralization at surfaces. (C) 1999 Elsevier Scienc e B.V. All rights reserved.